A load balancing mobility management for multilevel hierarchical mobile IPv6 networks

In order to reduce the number of binding updates (BU) when the number of connecting mobile hosts (MH) is limited for higher level mobility anchor point (MAP), a scheme adopting distributed location management (DLM) to multilevel hierarchical mobile IPv6 (M-HMIPv6) is proposed. In the proposed scheme, to avoid extreme load for higher level MAP, a threshold of the number of connecting MHs is set. When a MAP receives a BU and the number of connecting MHs exceeds the threshold, the MAP forwards the BU to the next MAP candidate. In addition, to reduce the number of BUs and extend a MAP domain, DLM is adopted in M-HMIPv6. The usage of the distance field in MAP option is modified to distinguish the route redundancy and keep transparency to HMIPv6. Moreover, to realize load balancing when mobility deviation exists, a load balancing by average BU interval in both access router (AR) and MH is adopted. By classifying MHs roughly by the average BU interval in AR, relatively faster MHs select higher MAPs. By performance evaluation using computer simulations, we show that the proposed scheme transparent to HMIPv6 can reduce the number of BUs and realize load balancing without excessive route redundancy.